RECON: TNO occultation with 12UE185

Event between 12UE185 and star GA0860:03625522 with event index number of 2111835

Geocentric closest approach at 2022/12/22 15:40:26 UTC

J2000 position of star is 08:52:11.8 -02:32:45
Equinox of date position of star is 08:53:19.1 -02:37:50
Stellar brightness G=15.6, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 120 degrees from the moon. Moon is 1% illuminated.
TNO apparent brightness V=22.2

TNO is 37.1 AU from the Sun and 36.5 AU from the Earth.
The TNO is moving 17.4 km/sec on the sky relative to the star, or, 2.4 arcsec/hr.
The 1-sigma error in the time of the event is 196 seconds.
The 1-sigma cross-track error in the shadow position is 1433 km.

The TNO has an absolute magnitude Hv=6.4
Diameter=306.2 km assuming a 5% albedo -- 17.8 sec chord
Diameter=125.0 km assuming a 30% albedo -- 7.3 sec chord
Dynamical classification is SCATEXTD
 
 
 
 
 
 
 
 

Star training set for 12UE185, (2022/12/22 15:38UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:09:35.6 +11:51:15  1.3 23.85 110
Alphard        09:28:43.0 -08:45:33  2.0 10.72 109
14 Hya         08:50:31.0 -03:31:46  5.3  1.14 120
PPM 191781     08:52:46.8 -03:22:12  8.3  0.75 120
PPM 177651     08:55:20.6 -02:33:57  9.0  0.50 120
PPM 177634     08:53:01.0 -02:18:15 11.0  0.34 120
12UE185        08:53:21.5 -02:38:00 15.6       120
Positions are for equinox of date

Azimuth is measured in degrees eastward from north. North is at an azimuth of 0, due East is at an azimuth of 90 degrees, due South is 180, and due West is 270.

Do not use the listing below for the RECON CPC 1100 telescopes. This is provided for other non-team facilities.

Star training set for 12UE185, (2022/12/22 15:38UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:08:21.9 +11:58:02  1.3 23.85 110
Alphard        09:27:35.2 -08:39:30  2.0 10.72 109
14 Hya         08:49:21.7 -03:26:35  5.3  1.14 120
PPM 191781     08:51:37.5 -03:16:57  8.3  0.75 120
PPM 177651     08:54:11.0 -02:28:39  9.0  0.50 120
PPM 177634     08:51:51.2 -02:13:01 11.0  0.34 120
12UE185        08:52:11.8 -02:32:45 15.6       120
Positions are for J2000

Event circumstances last updated at 2022/03/12 01:50:10 UT

Marc W. Buie, Southwest Research Institute

RECON